Battery-depolarizer.



tral manganites may be manufactured by MAJOR E. HOLMES, OF LAKEWOOD, OHIO, ASSIGNOR TO NATIONAL CARBON CO,

OF CLEVELAND, OHIO,

A CORPORATION OF NEW JERSEY.

BATTERr-DEPOLARIZER.

No Drawing.

To all whom it may concern:

Be it known that I, MAJOR E. HOLMES, a citizen of the United States, residing at Lakewood, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Battery-Depolarizers, of Which the following is a full, clear, and exact description.

One of the most important considerations in the choice of a depolarizer for dry cells is its effect on the so-called shelf life or de-.

terioration during periods of open circuitor inactivity. Some depolarizers having a high available oxygen content are very satisfactory during use, but if allowed to stand a considerable time they lose some of their depolarizing value.

The use of artificial depolarizers such as precipitated manganese dioxid and acid manganites is Well known and they have been found to possess very good depolarizing properties. Artificial manganese dioxid as well as other artificial depolarizers, however, are so expensive to manufacture in the re quired purity that their use is precluded in any but the smallest midget cells, and even in these the application is limited.

Other depolarizers on account of theiracidity are undesirable becaus a certain amount of acid will be liberated from the electrolyte which is usually neutral. Any acid thus formed will attack the zinc more or less and cause a consumption thereof which in time would make the battery useless. I have found that hydrated manganese dioxid and acid manganites on account of their acid reaction, possess this disadvantage, although as previously set forth they are satisfactory as far as their depolarizing value is considered.

To obtain a cheap, non-acid depolarizeris the object of this invention.

To prevent the foregoing deleterious action it has been found that neutral manganites may be used to advantage. a neutral manganite as a depolarizer does not permit the formation of any acid in the battery during the period of" inactivity so that the zinc will not be attacked nor the reaction of the electrolyte altered. The neu- The formulas of some of 1. In a dry cell,

The use of mixing hydrated manganese diom'd with a base such as calcium hydrom'd, sodium hydroxid, etc. Other reagents may also be used, that given being merely illustrative.

.Among the neutral manganites it has been found that the mangano-mangal iites are particularly satisfactory. .The'double manganites are also within the scope of my invention. the compounds included by.my invention are as follows; CaOMnO,;; MnO.MnO CaQKJ). (Mn- O CaO.MnO,.H O; Ca (N H,) .(Mn() etc. large number of these may be'expressed by the general formula; wMO.yMnO.zMnO,,. In this formula MO represents a base or metal oxid and may be combined in various proportions with the MnO and Mull, The coefficient a: of the MO portion of the compound as well as the coefficient 3/ of Mn() portion, may have values from zero up, but of course, both cannot be zero at the same time if a manganite is to be obtained. The coeflicient z of the MnO, portion of the compound may have a value of one or more. Since the compound is preferably dehydrated before being placed in use no water of hydration is given in the formula, but it will be understood that there is some present in the compound nevertheless before it is dehydrated.

Such compounds have an excellent depolarizing value and may be manufactured at a much lower cost than previous artificial depolarizers. They also prevent the liberation of acids which attack the zinc and produce the disadvantages previously set forth.

Having described my invention what I claim is:

compounds, which positive and negative electrodes and a depolarizer consisting of a neutral manganite.

23 In a drycell, positive and negative electrodes and a mix containing a plurality of neutral manganites as depolarizer.

lln testimony whereof, I hereunto afix my signature.

MAJ 0R 1E. H0! WEI; S, Witnesses:

' IRA J. ADAMS, 0

Specification of Letters Patent. Patigntedi Ftgb, 1W3, Application filed November 22, 1913. Serial No. 802,541.

It Will be understood there are a very 

